Let's do a Review Tandem ( double posting :/)
So I alluded to this prior, but after playing several games in the current metagame, I will say straight up, this is a bad Tandem submission. Both the head and the following Tandems are pretty bad, basically only a single redeeming character here, as currently showcased. Bad Heads + Great Tandems are a fun concept, a concept that is being explored multiple times in this very slate. Great Head + Bad Tandems is also a decent idea that has been explored since the metagame's conception (Garchomp is a great example). But bad heads leading bad tandems just don't make sense. I think the idea of utilizing ZU mons isn't horrible. Arboliva and Mabosstiff imo are mons that can very well only need a single buff to put them into at the very least competitive merit, and Mabosstiff has even arguably gotten exactly that. The rest of the squadmates including the head however, I think fall quite short.

Ok, addressing the head issue. Farigiraf is bad Indeedee. That's basically it. Even if we exclude the fact that Farigiraf cannot compete with almost every existing Head right now on paper, both with or without its Tandems in hand, even if we also note that Farigiraf has a mediocre at best matchup into other Heads (and many top tier Tandems). Fact of the matter is, even if we ignore the Tandems, there is zero reason I would pick Farigiraf over the likes of Indeedee. So this is already a major issue that low-key invalidates this mon. But if the Tandems are not only good enough as is, but also different enough from Indeedee specifically to justify its presence, then we would be good. (We aren't)

- Worse Arboliva set from standard. That's really all there is too it. I genuinely believe if you loaded one of standard ZU Arboliva's Sample Sets and inserted it as the Tandem it would be a more viable Pokémon. Tough Claws is just a massive misfire of a pick, Grass Knot isn't such a great move, and Arboliva isn't such a great mon to benefit from this in my opinion. Good Mon here, truly, but this was a bad execution of the concept.

- I like the concept of Sniper Frost Breath but Cryogonal feels a bit awkward as the option, mainly because it genuinely cannot touch any Fires and has a 50% chance to not be able to touch any Steels either. Ion think you can have it both ways with Tera here, you have a dead slot 50% of the time. Ice types with better options exist if you really want to go down this path imo, but even if you are adamant about Cryogonal pick better Tera types.

- The shining jewel of this Tandem, Jaw Lock + No Retreat is a notorious cheat code set that I think it can get a lot of mileage out of. That being said, the set could use a little tuning up. Firstly, I see the vision of Clear Amulet, but I think the chances of rolling it + Guard Dog is too much of a risk to run in my opinion. Parting Shot and Sticky Web are not particularly common, so Attack drops are the only real thing you need to wonder about, which imo you are more than covered for with Guard Dog. Id slap Black Glasses just so you can go a bit more offensive instead. TFangs are also weird, doesn't hit anything in the tier right now for damage that your other moves don't do. Fire Fang, Wild Charge, Destiny Bond, Psychic Fangs, possibly even Reversal probably serve as better options than what Thunder Fang does.

- The idea of Steel Trapping isn't flawed, I just think as of right now it's not particularly attractive, considering it has a bad matchup versus many of the Steels right now, or at the very least, has a mediocre trapping range right now. Forretress can eat a hit easily then pivot out or just heal off damage with Recover, Magnezone can also pivot out since it's faster, Cobalion can pivot out or 1v1 it with BPress, Heatran can just beat it since it's faster, often carries Air Balloon and knows Earth Power. Excadrill just wins almost every time and Kartana wins unless it locks into Knock Off (and honestly it still wins since it can't really do massive damage back.) I think you need to tighten up its Tera types, possibly it's move options (Explosion is genuinely useless for the role it's supposed to fill). I also think Air Balloon should arguably just be the sole item to ensure your matchups versus many of the Steels here (Heatran and Excadrill to say a few). It's job is to trap Steels so it's sets should be tailor made to ensure it can successfully trap said Steels.
Yeah, the team wants a touch up. A tune up. In some cases a full swap out. The Dog has legit merit, Arboliva can get merit if revamped. Imo the rest are here or there, and Farigiraf is just awful and should go pronto.
Flygon is worse Garchomp, and arguably worse Landorus-Therian too. However, I think even if I'd personally swap it out for another RU guy, Flygon seperates itself from its distinguished competition thanks to having strong Tandems who also serve as distinctly different from both Ground Head and their own Tandems. Honestly when you look at it, Flygon is somewhat an inverse of Garchomp. Flygon is worse Chomp, but Valiant is better Gardevoir, and Wash is better Rotom-Heat. It also has Bisharp and Talonflame, weaker mons that have gotten buffs that allow them to compete with standard OU fare while being different from whatever Lando and Chomp has to offer.

Not much to be said, it's worse Garchomp but I think with all of the choices made it was intentional - and Flygon can be usable as a whole lol.

- Valiant seems really good. Fairies are very strong, and even though the last slate has introduced a few forms of counterplay to them they have equally introduced new options to abuse. Two things to note, one that probably doesn't matter but is worth noting, and another that does. First thing is first, I don't think Ice Beam is a good idea to be running as a mandatory slot. Ice coverage is redundant with Fairy STAB, and Ice is a pretty bad Tera here. Id advice to get a different option and subsequent Tera, but ultimately this won't make Valiant a worse Pokemon, at least not a bad one. Second suggestion though is important. Booster Energy on Iron Valiant will always result in an Attack boost, making it 100% incompatible with your current set. I strongly urge you to either drop Booster or Swap it out for another item, or commit to the Attack boost and make Valiant a mixed attacker.

- I think the Mon is solid, however Bisharp doesn't know Knock Off in Gen 9, so it will have to be removed if you intend on keeping Steelworker. That's all really, it's an OK Tandem with a sweet (intended) upgrade.

- Talonflame is just a somewhat better version of an existing Talonflame Tandem, which is admittedly very lame. But it's not unviable, and again like I said, helps make it very distinct from both Chomp and Landorus-Therian. A fast Wisp imo would be pretty cool TBH if I were to offer a suggestion, as would Defog instead of Wisp.

- I love Rotom-Wash. Excellent Mon. Like as I said, I like the parallels with Chomp and Heatom. But I love Washtom more so I support this 100%. Really no notes, as this is just better Rotom-Wash, does so much for this team.
Team is solid, I'd look into ensuring you have sturdy defensive Weavile checks, at least one. That's something the other Grounds don't truly have as well, they depend on teammates for that. Otherwise, solid lineup.
Pretty consise build, genuinely extremely funny that every single Tandem has a horrible natural matchup into Weavile but simultaneously exclusively have Tera Steel as an option. I can only believe this is Hydrei's way to lure out and beat Weavile. Time will tell how effective it is, as Weavile's teammates don't struggle with Steels too much, and predictability in both the Tera types and the sets can put you in a disadvantage as well. Still, the Tandems are all very potent while its base is serviceable, so this will definitely be a viable and good set to run. Pray ChompVile doesn't become a big thing, kinda cooks you lowkey.

In order to justify the big gun Tandems I assume a weaker Head was picked, and Fez has a lot of great synergy with its teammates, so they can often pickup the slack. I'd say Fezandipiti in standard runs Beat Up, so its partners having exclusively shitty attacking stats sans Latios (who is ok) is funny to see. Otherwise by itself it's mid but with its Tandems it can work magic under skilled hands.

- It's Gholdengo, one of my favorite mons in Gen 9. It's a standard NP set with a potent Tera nuke to equip as well. The team can't set Spikes to take full advantage of GoG but teammates exist for that.

- A somewhat standard Mandibuzz set with the bonus of dodging set up with Unaware. Unfortunately most set up users are fully EV'd heads so it can only take so much, but it's still a REALLY solid option for bulky teams to exploit set up guys. The set particularly bullies Garchomp sets well if u maintained its non Tera Type (reason why I said Weavile forcing it to Tera might be annoying). All around solid pick here.

- Latios is an incredibly strong wallbreaker here, honestly might be a bit overkill to be honest. Not saying it's just outright broken, I just feel it pushes the envelope on what qualifies as a wallbreaker for Tandems. Still, it's coverage is rather limited between solely it's dual STAB, so I can see it being exploited as well.

- It's just Gen 8 Slowbro. Not a Mon I am particularly that fond of, but it's an ok pick all that's being said. It has a decent pairing with Mandibuzz and Fez as a wall core, a core that isn't necessarily busted up by anything we have right now, while still isn't necessarily a braindead wall core. Cool stuff all around.
Clefable our Lord and Savior. It's a solid pick and helps curb the Garchomps and Weaviles that are running amok, and the team has decent partnerships. Nothing outright bad and noteworthy to comment on, Clefable is a great addition to the metagame so I'll go straight into individual mon reviews.

- While I am not longer fiending for Gliscor since Lando is somewhat under control, Gliscor is a solid guy since it has so many positive matchups in this meta so far. Fire Lash is an interesting addition, I presume the goal is to combine Toxic + Fire Lash to force out switches. Solid stuff, I liked the SD sub but this is a good way of forcing progress against opposing teams.

- This was said before, but yeah Umbreon is kinda extremely passive with what was submitted. I presume Gliscor + Clefable allows for more passive play to be a thing. I personally think an ability will always serve Umbreon more than any one singular move. On the flip side, Clefable, Gliscor and Lunala are all very powerful, so maybe a somewhat mediocre Umbreon set can balance it out.

- It's an Uber, not much else to say here. Lunala is a pretty potent offensive Mon and has hella bulk and offensive prowess, I expect it to dominate versus the teams right now, as really it's only forced out by opposing Dark types, which it can probably play around. Strong as fuck potential balance breaker and overall great anti offense option.

- LO Mienshao is a classic offensive threat, and while it's speed is no longer a major selling point without max EVs, it's stills. Decent wallbreaker, especially if it gets off a strong Tera Fighting Close Combat here. Not sure if the option of Choice Scarf or maybe AV is an option, but just sticking to Life Orb is probably best.
Trick Room is annoying as hell, but I suppose it would be a niche solid option to run in an increasingly more aggressive offense based metagame. That being said, apparently if you like Bulky Offense, you can load that as an option as well, particularly if you role bulky juggernauts like Iron Hands and Ursaluna. However TR has an awkward angle in a meta where everything has 84 EVs...except for Heads and OU threats. Something like a Head Kingambit may prove disastrous.

Even outside TR, this is a pretty good Head, as it has a good matchup versus many top threats, and in a metagame with a lot more hazard setters than hazard removal, packing a Head like Hatterene is always gonna be useful.

- Strong as hell wallbreaker, Glacial Lance is a massive nuke option to smash up I presume a defensive Garchomp and Landorus-Therian threat without too much chip. Grounds are always welcome in the tier, as Electric types are slowly developing into dominant threats in the metagame right now, so Ursaluna will be beneficial whether or not it is a TR terrorist or a BO bastard. Great mon.

- I love Porygon2 as a Tandem piece, and even plan on including the guy in the future, but holy fuck is this a fun ass set. Hyper Beam sounds so fun to abuse so much I wish Tera Normal was an option to abuse it. Either way, it's a good secondary TR setter / abuser for a team, and can probably do it's job pretty well.

- Imo it's the Mon that ties it altogether, Iron Hands is a solid wallbreaker that may he's up well versus many threats. Trade machine extraordinaire. I just see it as an effective bulky Wallbreaker and fits alongside many of the BO tandem squads. Already looking forward to rolling this guy.

- This is a genuinely unique take on Skeledirge, with Magic Guard making this guy alot more splashable wallbreaker. With it being so offensively leaning, I think just streamlining the Tera types to just let it score the STAB on Alluring Voice 100% of the time is the right way to go. Genuinely seems like a fun mon so I look forward to seeing it play out in the future the tier if it wins.
All around some cool subs this round, I look forward to seeing how they evolve and what we should expect next going forward.